Most coaches know whether a session felt hard. Few have a reliable system for quantifying it, and that gap matters when you are managing 10 athletes with different fitness levels, training histories, and recovery rates.
Rate of Perceived Exertion (RPE) is the closest thing to a universal training load metric. It requires no heart rate monitor, no power meter, no lab. Since Carl Foster formalised the session-RPE method in 1998, it has been validated in 36 studies across dozens of sports, age groups, and training populations, with more than 950 published studies citing the approach.
What RPE Actually Measures
RPE is not just a rough feeling. The most widely used version in sport and coaching is Borg's CR-10 scale, which runs from 0 (rest) to 10 (maximal effort, nothing left). Athletes rate how hard the *entire session* felt, approximately 30 minutes after finishing, not mid-set or at the final whistle.
The session-RPE load formula is:
Session load (AU) = CR-10 rating × session duration (minutes)
A 60-minute session rated 7 out of 10 produces 420 arbitrary units of load. A 90-minute session rated 5 produces 450. This converts a subjective feeling into a trackable number that can be summed weekly, trended across months, and compared across athletes regardless of their sport or discipline.
Reliability figures are strong. Day and colleagues reported an intraclass correlation of 0.88 for session RPE across high, moderate, and low intensity lifting. A separate study found an ICC of 0.95 with a coefficient of variation of 17%. A 2017 systematic review by Haddad and colleagues examined 36 validation studies and concluded that session-RPE can function as a standalone training load monitoring tool across sports and age groups, with no requirement for physiological equipment.
Load Zones and Weekly Targets
For coaches managing a squad, raw load numbers are more useful than RPE ratings in isolation. The table below shows approximate weekly session-RPE load ranges by training phase, expressed in arbitrary units:
| Training phase | Typical weekly load (AU) | Notes |
|---|---|---|
| Off-season / base | 1,500–2,500 | High volume, low to moderate intensity |
| Build / general prep | 2,500–3,500 | Volume and intensity both rising |
| Competition prep | 2,000–3,000 | Reduced volume, maintained intensity |
| Taper | 800–1,500 | Sharp volume drop, intensity held |
| Deload / recovery | 600–1,200 | Full recovery week |
These ranges are sport-specific and athlete-specific. What matters in practice is the change relative to each individual's baseline, not the absolute number. A 30% week-on-week spike in training load is consistently associated with elevated injury risk in team sport research (Gabbett, 2016).
The acute:chronic workload ratio (ACWR) gives coaches a standardised way to track this. Divide an athlete's 7-day rolling load by their 28-day rolling average. An ACWR above 1.5 is associated with heightened injury risk in the following weeks. An ACWR below 0.8 suggests the athlete is accumulating less stress than their long-term average, which indicates either planned recovery or unintended detraining.
Applying This Across Multiple Athletes
This is where session-RPE's simplicity becomes a genuine practical advantage. A coach managing 15 athletes cannot collect heart rate or velocity data from every session for every person. Session-RPE takes under 30 seconds per athlete and applies equally to gym sessions, track workouts, field training, and pool work.
A consistent workflow:
- Athlete rates the full session on the CR-10 scale, 30 minutes post-session
- Multiply rating by session duration to get session load in AU
- Sum weekly totals and calculate each athlete's rolling ACWR
- Flag any athlete whose ACWR exceeds 1.5, or who shows a sustained drop in RPE at the same planned intensity (which can indicate either positive adaptation or undereporting)
The undereporting problem is significant and well-documented. Research comparing coach-estimated session RPE with athlete-reported ratings found correlations of only r = 0.58 to 0.64, with coaches consistently underrating how hard individual athletes found shared sessions. A coach cannot accurately gauge each athlete's experience of a group session. The only reliable data comes from the athletes themselves, collected consistently and privately.
Compliance with reporting is the operational challenge most coaches underestimate. Research shows athletes who receive visible feedback on their monitoring data report significantly more consistently than those who submit ratings with no apparent outcome. If athletes never see how their load data is being used to adjust their programme, they stop providing useful numbers.
How PROTR Handles RPE Coaching
PROTR is a free coaching and training app that logs RPE on every set and session. Athletes rate each workout on completion; coaches see a compliance dashboard showing who has and has not logged across all their training groups. TSS is calculated per session and the Performance Management Chart (CTL, ATL, TSB) updates for each athlete. Habit and check-in tracking complete the readiness picture alongside load data. Free for coaches and athletes.
Download PROTR on the App Store
Common Mistakes
Collecting RPE immediately after the session. Ratings taken under acute fatigue are inflated compared to those taken 30 minutes later. The delay is not arbitrary: it is what the validation studies used.
Ignoring outliers. A session rated 9 after a planned moderate day is data, not noise. Sleep, stress, or illness may be a factor. Follow up with the athlete rather than averaging it away.
Comparing absolute load numbers across athletes. A 3,000 AU week is not the same for a 55 kg middle-distance runner and a 110 kg strength athlete. Track each person against their own rolling baseline.
Relying on your perception of group effort. The research is clear: coaches consistently misread how hard individual athletes find shared sessions. Collect the data. Do not guess.